Pedigree structure of HSP family (SPG54) and sequence confirmation of the DDHD2 mutation. a Family pedigree. Squares and circles indicate males and females, respectively. Darkened
symbols represent affected members, and slashes represent deceased. b Representative sequence traces of subjects and control. Sanger sequencing confirmed the homozygous nonsense mutation (c.859C >T, p.Arg287*) of the DDHD2 gene identified in the probands (IV-1, IV-3, IV-7, IV-8). The control sequence trace demonstrates the wild-type sequence. c A schematic illustration of DDHD2, showing four protein domains [WWE, lipase, coiled–coiled region (SAM), and DDHD]. The positions of all identified mutations are indicated. The mutation identified in this study is indicated in red.